Re: [PATCH v2 1/8] drm/virtio: Correct drm_gem_shmem_get_sg_table() error handling

[Dmitry Osipenko]

On 3/15/22 01:42, Dmitry Osipenko wrote:
> drm_gem_shmem_get_sg_table() never ever returned NULL on error. Correct
> the error handling to avoid crash on OOM.
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/virtio/virtgpu_object.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
> index f293e6ad52da..bea7806a3ae3 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_object.c
> +++ b/drivers/gpu/drm/virtio/virtgpu_object.c
> @@ -168,9 +168,11 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
>  	 * since virtio_gpu doesn't support dma-buf import from other devices.
>  	 */
>  	shmem->pages = drm_gem_shmem_get_sg_table(&bo->base);
> -	if (!shmem->pages) {
> +	ret = PTR_ERR(shmem->pages);

This actually needs to be PTR_ERR_OR_ZERO. This code is changed to use
drm_gem_shmem_get_pages_sgt()+IS_ERR() by the further patch, so I just
missed the typo previously. I'll correct it in v3.